Embodiments of the present invention relate to a concept for bidirectional data transmission between a base station and a node. Further embodiments of the present invention relate to a base station including bidirectional data transmission to a node. Further embodiments of the present invention relate to an optimized bidirectional base station-node telemetry system.
When transmitting small amounts of data from a large number of nodes to a base station, such as, for example, sensor data of heating, electricity or water meters, and when transmitting control information from the base station to the nodes, such as, for example, when switching on/off devices, a radio transmission system may be used. Here, the base station receives and controls a large number of nodes.
There are different unidirectional and bidirectional systems for transmitting data between the base station and the nodes. Known systems are, for example, DECT (digital enhanced cordless telecommunications) and RFID (radio frequency identification). Typical of these systems is the fact that the base station sets a reference frequency and a reference time which the nodes synchronize to. Exemplarily, in RFID systems, a reader (base station) sets a time window, which follows directly after being sent out, within which the RFID transponders (nodes) randomly choose a time for responding. The predetermined time interval is additionally subdivided into time slots of equal length. This is called a slotted ALOHA protocol. In DECT, time slots are provided within a fixed predetermined pattern. Here, the base station associates to a participant an exact time slot which it may use for communication. Due to the inaccuracy caused by the quartz tolerance, a buffer time is provided in between the time slots in order for the data packets not to overlap.
The object underlying the present invention is providing a concept which allows increasing the range and/or data transmission rate or channel capacity (number of participants or users).